Testing if display approx. 140.0 °C

-- Disconnect the Engine Coolant Temperature Sensor -G62- or Engine Coolant Temperature Sensor On Radiator Outlet -G83- electrical harness connector.

-- Switch the Ignition On.

If indication jumps to approx. - 40.0 °C: 

-- Switch ignition OFF.

-- Replace the Engine Coolant Temperature Sensor -G62- or Engine Coolant Temperature Sensor On Radiator Outlet -G83-

If the value remains at approx. 140.0 °C 

Checking wiring 

If the manufacturers test box is being used, perform the following step. 

-- Install the test box.

If the manufacturers test box is not being used, perform the following step. 

-- Remove the Engine Control Module (ECM) -J623- and disconnect the ECM connectors.

-- Disconnect the ECT harness connector at the sensor.

-- Using a multimeter, check the signal circuit of the Engine Coolant Temperature Sensor -G62- or Engine Coolant Temperature Sensor On Radiator Outlet -G83- electrical harness connector terminal 1 to engine ground.

Specified value: OL or no continuity.

If the specified value was Not obtained: 

-- Check the wiring for a short circuit to Ground.

-- Check the electrical harness connector for damage, corrosion, loose or broken terminals.

-- If necessary, repair the faulty wiring connection.

If the specified value was obtained: 

-- Replace the Engine Control Module (ECM) -J623-.

Final procedures 

After the repair work, the following work steps must be performed in the following sequence: 

1. Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY .
2. If necessary, erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
3. If the DTC memory was erased, generate readiness code. Refer to READINESS CODE .